A CONNECTION BETWEEN FURNITURE LEGS

Abstract: A connection between furniture legs is obtained by means of a pullrod (5) which is axially mounted in furniture legs (1, 2). Pointed screws (11) in bushes engage depressions in the rod (5) in order that tightening causes both joining and resistance to rotation.

Description: A connection between furniture legs. The invention concerns a connection which enables a stable extension of furniture legs. Connection methods are known for furniture legs, such as from Danish Utility Model DK92 00086 U3 which outwardly appear with as few disturbing elements as possible. The connection described in the said publication is strong and good, but the best stability is obtained when the tolerances are small, and when the material of the furniture leg proper is wood, theese will be exceeded when the humidity changes. Ideally the connection occurs between pieces of wood which have been cut out of one and the same trunk of one and the same tree, and this is only possible in exceptional cases. Hence there is a need for a connection which displays the same advantages as to strenght, which are just as easy or easier to establish but which does not have such large requirements as to tolerance. It has been realized that tolerances on lenght (i.e. along the fibres) of wood are much easier to keep than tolerances across the fibres, even with varying degrees of humidity. Hence there is a possibility that a connection which is capable of pulling two lenghts of wood towards each other end to end may be made with close tolerances. There is a need for a force which is so large that the connection appears as a unbroken piece of wood, possibly larger. This is obtained in a connection for furniture legs according to the invention which is peculiar in that it comprises a cylindrical bore in the axi of each furniture leg, into which fits a pullrod with at least one radial through hole and a recess on one side of it, that a least one bushing with a hole which fits closely around the pullrod is fitted in at least one crosswise disposed well in the furniture legs, and that at least one pointed screw is placed in a threaded hole which is perpendicular to the hole o the bushing. When the pointed screw is tightened, its point cooperates with the recess and presses the bushing against tha part of the well which is closest to the end of the furniture leg. Since it is necessary that the steel rod is fastened securely in both furniture legs, but may at the same time be removed completely, a preferred embodiment has two through holes, bushings, and pointed screws, whereby the distance between the bushings is greater is greater than the distance between the centre lines of the radial through holes in the steel rod. A further advantageous construction is obtained when the pointed screws are made of steel and with an angle which corresponds closely to the recesses in the through holes in th steel rod. Thus it is obtained that tightening the pointed screw will cause a secure tight connection without wear on the parts of the construction. A further advantageous construction is obtained in that the steel rod has a further length further out from the throug holes which corresponds to the lenght of the bushings fitted into the wells. Thereby a further assurance of maintaining stiffness is obtained which is partly based on the fact that i is prevented that the steel rod bends when the pointed screws are tightened. The invention will be described in greater detail in the following with reference to the drawing, in which Fig. 1 shows a general arrangement of a furniture leg with an extension, and Fig. 2 shows a longitudinal section through a connection according to the invention. In Fig. 1 is shown a leg l of a bed with an extension 2 which must be connected in a stiff and rotation resistant manner to 1. This is obtained in the connection 3 which is shown in almost full size n Fig. 2. The stability against rotation is obtained by means of bushings 4, 4 which in their tightened condition are fitted in a rotation resistant manner to the through rod 5 and the leg 1 and the extension 2 at the wells 6, 6 which have been drilled from the side. The rod 5 fits closely in a cylindrical bore 7 in the axis of the bed le 1 and the extension 2 with a tolerance which is as narrow as possible with regard to the fact that the rod must be able to be fitted and removed again. The rod 5 has radial through hole 8,8 which at one end have recesses 9, 9 . These cooperate wit points 10, 10 on pointed screws 11, 11 which are fitted in threads in the bushings 4, 4 . The bushings may be cylindrical or square, and they are provided with through hole of the same diameter as the rod 5 and at right angles to it, and the threa mentioned for the pointed screw 11, 11 has been cut in the lenghtwise direction in the said bushing. The bushings fit in the wells 6, 6 which may be drilled or cut, dependent on whether the bushings are cylindrical or square. The rod 5 and the bore 7 have been extended away from the joint with a lengh L which corresponds to the lenght of the bushings 4, 4 and which a.o. serves to distribute the considerable side force which the end of the rod 5 is subjected to during the tightening, in particular because the cross section of the rod has been weakened because of the trough holes 8, 8 . During assembly the bushing 4 is introduced into the well 6, and the rod 5 is put into the through hole of the bushing through the bore 7 inn the leg extension 2, whereafter the pointed screw 11 is screwed in without tightening. The bushing 4 is introduced into the well 6 , and the part of the rod 5 which protrudes from the extension 2 it introduced into the be leg and through the trough hole in the bushing 4 . Hereupon the pointed screw 11 is tightened, until a suitable torque has been reached. Since the points 10, 10 are not to bottom in the two recesses, it is possible to absorb possible deviations fro the specified lenght of the bed leg 1 and the extension 2, and the angle of the point establishes a large force lengthwise along the bed leg through the rod 5. The top angle of the point determines the lever ratio between the torque of the pointed screw and the pulling force (taking the friction into account) , and the material for the rod and the pointed screw, preferably steel, ensures that the screw not just bites into the rod. This would admittedly ensure that a certain rotation resistance we obtained, but the pulling force would be reduced. In case it is no longer necessary to have an extended be leg, e.g. because bunk beds are no longer to be used in this manner, but next to each other, the connection may be taken apart again and removed.

Claims: P A T E N T C L A I M S 1. An axial connection for furniture legs c h a r a c t e r i z e d i n that it comprises a cylindrical bore in the axis of each furniture leg, into which fits a pullrod with at least one radial through hole and a recess on one side of it, that at least one bushing with a hol which fits closely around the pullrod is fitted in at least on crosswise disposed well in the furniture legs, and that at least one pointed screw is placed in a threaded hole which is perpendicular to the hole of the bushing. 2. An axial connection for furniture legs according to claim 1, c h a r a c t e r i z e d i n that both furniture legs are provided with bores, wells, bushings, and pointed screws, in which the distance between the bushing is greater than the distance between the centre lines of the radial through holes of the steel rod. 3. An axial connection for furniture legs according to claim 1, c h a r a c t e r i z e d i n that the pointed screws are made of steel and with an angle which corresponds closely to the recess in the through holes in the steel rod. 4. An axial connection for furniture legs according to any of the preceding claims, c h a r a c t e r i z e d i n that the steel rod has a further lenght outside the through holes which corresponds to the lenght of the bushings fitted into the wells.

Inventors: JENSEN HENNING LYKKE, JENSEN, HENNING, LYKKE
Applicants: JENSEN HENNING LYKKE, JENSEN, HENNING, LYKKE
Application year: 1994
Main classification: F16B12
IPC codes: A47B9, A47B91, A47C3, A47C19, F16B12